The Saline Water Conversion Corporation, Research an Development Center (SWCC-RDC) carried out exploratory research study to evaluate the adaptability of the brackish water softening nanofiltration technique as a permeation pretreatment of feed to seawater reverse osmosis (SWRO) and as make-up to MSF. This exploratory work was designated as part I of an applied research project that was carried out from March 1997 to May 1998. Based on initial remarkable results, SWCC applied for a patent on the process during 1997. This paper reports on the pretreatment approach and its application to thermal desalination using MSF. The work carried out in part I of this project is reported where make-up to a 20 kiloliter/d MSF pilot plant distiller was either fresh nanofiltration permeate (NFP) or SWRO reject (while SWRO was fed with NFP). This paper also addresses the plan of elevating MSF top brine temperature (TBT) to as high as 160 degrees C since operation at TBT of 120 degrees C with very little or no scale control treatment gave excellent results.